J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from J. Neurol. Neurosurg. Psychiat., 1949, 12, 251.

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CRAMP IN CASES OF PROLAPSED INTERVERTEBRAL DISC BY LIONEL WOLMAN From the Department of Nervous Diseases, Royal Sheffield Infirmary and Hospital Although cramp has been mentioned as a symp- This procedure has since been abandoned in favour tom by several writers on the subject of prolapsed of complete curettage of the disc space. Of the 204 intervertebral discs (Bradford and Spurling, 1941; patients, 142 had division of one or more p6sterior ro6ts, O'Connell, 1943; Lenhard, 1947) no study has while the remaining sixty-two had no such division. The surgeon's decision whether to section the posterior hitherto been made of its exact nature, frequency, root was influenced by his estimate of the completeness and relationships. It was not until the routine of the disc removal and to a lesser extent by the severity follow-up of cases of sciatica, which had been of root pain. treated surgically, was begun that it was noticed that the symptom of painful cramps in the leg was fairly Type of Cramp.-In most cases the cramp came common in postoperative cases. This served to on at night while the patient was in bed. It affected focus attention on the symptom, and an inquiry the calf alone, the thigh alone, the foot alone, or

about it was therefore made in all cases, both before combination of these. There was always associated Protected by copyright. and after operation. The purpose of this paper is pain, and the patient could always feel the muscle to record these observations, and if possible to harden or, in the case of the foot, see and feel the relate the' symptom to conditions found at, or toes being drawn down under the sole. These produced by, the operation, and to discuss the symptoms were always verified before a pain in the symptom in relation to theories now held on the leg was-called cramp. atiology of muscle cramp. When there had been cramp before operation, this symptom began after the onset of sciatica and Material never before. The most characteristic thing about The observations recorded here were made in the the postoperative cramps was that they were very Department of Nervous Diseases, Royal Sheffield frequent immediately after operation, occurriig Infirmary and Hospital, in a series of 204 cases of back- for ache and sciatica which were thought to be due to nightly or every other night the first few weeks, herniation of an intervertebral disc and were subjected and gradually becomi'ng less frequent so that they to operation. The patients were operated on between occurred about weekly or monthly twelve to the years 1939 and 1946 by Mr. James Hardman, and a eighteen months after operation. With a further routine follow-up examination was carried out in 1947, lapse of time they became very infrequent, occurring at least twelve months and up to seven years after only once every three or- four months. This operation. The figures given below are extracted from infrequency made observations on actual attacks http://jnnp.bmj.com/ the complete follow-up survey carried out by the writer, of cramp difficult. None have yet been recorded the results of which will be published in a later paper. as occurring more than five years after operation. Type of Operation.-The operation performed was either a laminectomy or a hemilaminectomy, with Incidence of Cramp.-Cramps occurred as a pre- exploration of the disc spaces between the fourth and operative symptom in sixteen out .of the 204 cases fifth lumbar vertebra and the lumbosacral articulation. in the series (8 per cent.). It occurred after As much prolapsed material as possible was removed, operation in fifty-two cases (26 per cent.). Of

and if exploration was negative further spaces were these postoperative cases, in the group of sixty-two on October 1, 2021 by guest. investigated if this wa's thought necessary by the cases not having a sensory'root divided, nine (15 operating surgeon. In about two-thirds of the cases per cent.) developed cramps, whereas, in the 142 division of one or two sensory roots, either at the same cases having a posterior root division, forty-three segmental level as the disc or at the segment above, was made. This procedure was adopted in' an attempt to (30 per cent.) developed cramps. Thus cramps be certain that pain was relieved (Walker, 1945) and to appear twice as commonly in the cases having -avoid further root pressure if more material should division of sensory roots as in those not having prolapse. this performed. 251 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from

0, .~~~~~~~~~~~~~~~~~~~~~~~~ 252' LIONEL- WOLMAN TABLE I Precipitating Cause of Cramps.-AII the patients AGE AND SEX INCIDENCE OF CASES- were asked what factors brought on the cramp. The replies (Table II) showed that nocturnal cramp Series ino Average Age of Aof Men Women occurred in more than half the cases. series age youngest e est Pre- operative Factors Relieving Cramp.-The cramp passed of cramps .. .. 16 38 20 54 15 1 Postoperative spontaneously in all the patients in whom it cramps . . .. 52 36 17 50 43 9 occurred pre-operatively, but could be relieved by Cases without cramp .. .. 136 36 17 68 112 24 rubbing the affected part or by pressing the foot Whole series .. 204 36 17 68 170 34 against something firm. In the fifty-two patients in whom cramp was postoperative, changing -the position of the leg was most effective and relieved Of the sixteen patients complaining of cramp in before operation, ten were relieved of this symptom cramp fifteen cases, pressing the foot to the after operation, while in the remaining six the ground was successful in ten, and six found that cramps were6 more frequent and severe afterwards rubbing the affected part gave relief. Three patients in all but one, whose cramps persisted at about the thougzht they could relieve cramp by taking aspirin same frequency and intensity. It has been men- before going to bed, and eight cases used'a combina- tioned already that the cramp in these cases tends TABLE 1II to come on at night while the patient is in bed, thus differentiating the pain from that of inter- MUSCLES AFFECTED BY CRAMP mittent claudication. A further point of difference Pre-operative cases Postoperative cases is the age incidence, which is shown in Table I. Part Weak- Weak- It will be seen that the average age of the -atients affected Weak- ness Weak- ness was the same as in No. % ness and No. % ness and with cramp approximately the Protected by copyright. only wast- only wast- whole series of sciatica cases; this suggests that ing ing vascular factors of a degenerative type play no part in the causation of the cramp. Thigh .. 2 13 0 1 3 6 1 2 Thigh and Sex Incidence.-The sex of the patients with calf .. 1 6 1 0 6 11 0 1 cramp is shown in Table I. Although pre-operative cramps were commoner in men than in women, the Calf .. 9 56 5 4 29 56 10 5 sex distribution in the group with cramp after Calf and foot 1 6 1 0 5 10 0 0 operation was similar to that for the whole series Foot and toes 3 19 1 0 9 17 2 2 (about five men to one woman); this suggests Total.. 16 100 100 that sex has no part in the aetiology of these cramps. _-52 II tion of all these methods to obtain relief. The - TABLE remaining ten adopted no particular measures but PRECIPITATING FACTORS IN CRAMP allowed the cramp to pass off spontaneously. No. with No. with Precipitating factor pre- post- Site of Cramp.-The muscles affected by cramp operative operative are indicated 'in Table III. As many observers cramp cramp have previously noted, the calf m'uscles are -by far http://jnnp.bmj.com/ the commonest site for muscular cramps. In the In bed at night ...... 7 32 sixteen pre-operative cases, wasting of the affected muscles was found in five patients, while in all While bending or kneeling .. 0 3 except three there was definite weakness of these While sitting ...... 2 3 muscles compared with the opposite side. Fibrilla- tion was seen in the calf in two patients only. In Stretching leg ...... 2 0 the fifty-two postoperative cases weakness and on October 1, 2021 by guest. While standing with weight wasting were less frequently found in the affected on leg...... 0 3 muscles, there being ten patients with wasting and twenty-three with weakness. As cramps were No definite cause-cramp at fairly infrequent by the time of the follow-up, this any time of day or night .. 5 11 observation is of doubtful significance. The dis- tribution of the weakness and wasting is shown in Total . .. .. 16 52 Table III. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from CRAMP AND PROLAPSED DISC 253. TABLE IV medial or lateral position, there is no definite RELATIONSHIP OF CRAMP TO THE LEVEL OF THE correlation between the muscle affected by cramp PROLAPSED DISC and the level of the prolapsed disc. The type of disc found at operation, especially as regards the Cases with Cases with Remainder pre- post- of cases position of prolapsed material, was therefore Site of prolapsed operative operative without disc tramp cramp cramp investigated next. / No. % No. % No. % Relationship of Cramp to Type of Disc.-The type of disc found at operation had to be discovered L3-L4 ..' 0 0 0 0 4 3 from the operation notes, but in some cases no L4-L5 .. . 5 31 16 31 50 36 particular comments about the disc were found.,' L5-Sl .. 9 56 31 60 72 54 It was possible to divide the cases in which special L4-5 and L5-S1 0 0 4 8 6 5 comment was made into four categories according No disc found at to whether the prolapsed disc appeared as a slight operation , .. 2 13 1 2 4 3 medial bulge, a large central prolapse, a small Total .. 16 100 52 101 136 101 lateral prolapse, or a large lateral prolapse. This The degree ofweakness and wasting ofthe muscles TABLE VI liable to develop cramp was not significantly RELATIONSHIP OF CRAMP TO TYPE OF DISC different from that seen in cases not developing Pre- Post. cramp either before or after operation. operative operative Rest of and Level of Type of cramps cramps series Cramp Prolapsed Disc.-The relation- prolapsed ship of cramp to the level of the prolapsed disc disc No. No. found at operation was also investigated. Table IV % % No. % Protected by copyright. gives an analysis of the site of the prolapsed disc in No evidence of the various groups. From this it will be seen that prolapse .. 2 13 1 2 4 3 the distribution is approximately the same in all Slight median three groups, which suggests that the occurrence of bulge.. .. 2 13 15 29 32 23 cramp is independent of the level of the prolapse Large central pro- lapse . .. 3 19 21 41 56 41 of the disc. Small lateral pro- lapse . .. 2 13 1 2 12 ,9 Site of Cramp and Level of Prolapsed Disc.-In Large lateral pro- Table V the relationship between the site of cramp lapse.. .. 7 44 10 19 20 15 and the level of prolapsed intervertebral disc is No mention made shown both for the group suffering from cramp of disc type .. 0 0 4 8 12 9 before operation and the group with postoperative Total .. 16 102 52 101 136 100 cramp. As is to be expected from the fact that a pro- lapsed disc can affect the nerve root either of its is obviously an arbitrary and artifiial division, as own or of a higher segmental level according to its the static conditions seen at operation may not represent the true state of affairs, but it was the only TABLE V method possible. In Table VI the findings are http://jnnp.bmj.com/ RFLATIONSHIP BETWEEN SITE OF CRAMP AND LEVEL compared with those obtained in the 136 cases OF PROLAPSED DISC without cramps. The findings in the cases develop- after those in Pre-operative J Postoperative ing cramp operation resemble the Part cramp cramp general series, but in those suffering cramp before -affectedby No L5A No operation there was a higher proportion with large cramp L4-L5 L5-SI disc L4-L5 L5-Sl and disc lateral prolapsed discs. These figures suggest, found L5-S1 found therefore, that cramps are more liable to develop Thigh.. 1 1 0 3 0 0 0 in cases having a large lateral prolapse of the disc. on October 1, 2021 by guest. As the nerve root was often stretched over the and calf 0 1 0 1 5 0 0 summit of the large prolapsed discs, attention was Calf .. 2 6 1 8 19 2 1 next focused on the posterior nerve root. Calf and foot .. 1 0 0 1 1 1 0 Cramp and the Posterior Root Section.-It was Foot and found that most of the fifty-two patients developing toes .. 1 1 3 6 1 0 postoperative cramp had one or more- posterior ... I t , . .. L I. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from --L-INEL VOLMAN - : nere roots sectioned at operation. Thus, only,> TABLE VIII nine patients (18 per cent.) -did not have a' root RELATIONSHIP OF CRAMP TO RESULT OF OPERATION IN dividedjwhile- 83 -per cent. did, 54 per cent. having PATIENTS WrTH CRAMP BEFORE OPERATION- division of one sensory root and 29 per cent. having Good Bad two. Of the patients with cramp and without Series Number result result sensory root division, one had paraplegia before in series - operation which persisted afterwards and at opera- No. % No. % were found to tion the roots of the cauda equina Cases with cramp before be-matted together, three had very laterally placed operation >. .. 16 9 56 7 44 discs with the nerve root stretched over the summit of -the disc, and the remaining five had nothing Remainder of series .. 188 120 64 68 36 special recorded about the operation. It is worth Whole series .. 204 129 63 75 37 noting that in only one patient out of the fifty-two developing cramp after operation was the cramp bilateral in both calves. This patient was the only per cent. showed no abnormality, while 18 per cent. one in whom the posterior root was divided on both had narrowing of the disc space and 12 per cent. sides. The patient who complained most bitterly had arthritis. Of the 136 patients who never of all about painful cramps in the calf had only a experienced cramp, 44 per cent. showed no abnorm- partial division of one posterior nerve root. (Table ality, 17 per cent. had narrowing of the disc space, VII.) and 14 per cent. had arthritic lipping. The radio- graphs in the group developing cramp after opera- TABLE VII tion and in the general series were taken at the time CRAMP AND POSTERIOR ROOT SECTION of the follow up, when arthritic changes, if any, Roots sectioned would be at their maximum. The fact that the

x-ray appearances of the lumbar spine in the casesProtected by copyright. Part affected by L4 L5 L4 L5 S1adin None cramp developing cramp were roughly similar in type and 5 Si frequency to those of the general series suggests

Thigh .: .. 1 1 0 1 that arthritis had little or no part in the etiology of these cramps, while in the pre-operative group it Thigh and calf.. 1 3 1 0 0 1 played no part whatever. Radiographs taken at 2 3 3 7 3 11 Calf .. . the time were little or no different from those taken Calf and foot.. 1 1 0 2 1 0 before operation, the variation being no more than 0 0. Footand toes ..0. 3 3 3 in the group not developing cramp. Total . 6 19 3 8 7 9 (12%) (36%) (6%) (15%) (13%) (18%) Relationship of Cramp to Results of Operation.- An investigation was made into whether patients Site of Cramp and Posterior Root Section.-An who had cramp before operation did better or worse attempt was made to correlate the muscle affected than those without cramp at that stage. More by cramp with the root divided. Although there detailed results will be published later, and here the was a tendency for the thigh muscles to be affected 'cases are merely divided into good and bad. The when the fourth lumbar root was divided and for results are without significance. (Table VIII.) the foot to be involved when t1W fifth lumbar and first sciatic roots were divided, there were exceptions, TABLE IX http://jnnp.bmj.com/ as might be expected from the fact that there is an RELATIONSHIP OF CRAMP TO RESULTS OF OPERATION IN overlap between the muscles and cord segments PATIENTS DEVELOPING CRAMP AFTER OPERATION supplying them, each muscle being supplied by more than one segment and each segnental level Good Bad supplying several muscles. Cases with cramp No. result result Relatibnship of Cramp to X-Ray Appearamnes.- No. % No. % in with As muscular cramps are common patients One or more root divided .. 43 28 65 15 35 on October 1, 2021 by guest. arthritis of the knee, hip, or spine (Pem-berton, .. .. 9 5 56 4 44 1935), the x-ray appearances were studied. It was Norootdivided found that in the pre-operative group 44 per cent. Total with cramp .. 52 33. 64 19 36 showed no abnormality of the lumbar spine on x-ray examination, while 38 per cent. had slight Cases without cramp .. 136 87 64 49 36 narrowing of the disc space and none showed Whole series .. .. 204 129 63 75 37 arthritic changes. In the postoperative group 46 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from CRAMP AND-PROLAPSED DISC TABLE X whole series (Table XI). In the patients with OPERATIVE PROCEDURE ON SIXTEEN PATIENTS WITH CRAMP cramp-before operation the duration of symptoms BEFORE OPERATION was slightly less than in those without it, suggesti'ng Dis that there was no relationship. In contrast, the ofcNo disc patients with cramp after operation had a much cmremovalDcDic f removal .and fon;Totalno longer duration of symptoms before surgical only pseirnerve treatment; this was especially so in the patients onsectionSection who had cramp without root section. The longer duration of symptoms suggests the possibility of No. of cases with more damage to nerve roots by prolapsed material, cramp before but whether this is the correct explanation is operat-ion only 3 6 1 10 doubtful in view of the short histories in the patients .No. of cases with with pre-operative cramp. It seems likely that the- cramp before duration of stretching of nerve fibres by prolapsed a n d a f t e r material is only one factor, and possibly of less operation .. - 0 5 1 6 importance than the size and site ofprolapse. The next point investigated was whether, in Cramp and Type of Symptoms.-All the 204 patients developing cramp after operation, the patients under review had sciatica, but there were cramps occurred more commonly in the operative five without any backache and eleven with slight failures or in the successes. It will be seen that the pain in the back compared with that along the results are approximately the same in the groups sciatic nerve distribution. Of these five without with and without cramp as compared with the whole backache, two had cramps in the calfafter operation. series and therefore the appearance of cramp after All the remaining patients had both backache and operation has no prognostic significance. sciatica; and, although it was difficult to estimate Protected by copyright. (TableIX.) accurately, the impression was that there was little Persistence of Cramp after Operation.-Of the or no relationship between severity of sciatic pain sixteen patientk with cramp before the operation, and the occurrence of cramp. It may be argued only six had it afterwards, the remaining ten being that the occurrence of cramps after operation was free. The operative procedures carried out on these more dependent on the severity of pain due to nerve patients were as given in Table X. root involvement than on root section, and that the latter procedure happened to be done only in Cramp and Duration of Symptoms of Prolapsed the patients with severe pain. The longer duration Disc.-In order to see if there was any relationship of symptoms in the patients with cramp after between the occurrence of cramp and the length of operation is compatible with the greater nerve history before operation, the average duration of involvement in these cases. Often, however, the symptoms of prolapsed intervertebral disc for the nerve was sectioned irrespective of the severity of various groups was compared with that of the pain,, and sometimes this was done because of the small amount of prolapsed material removed. As TABLE XI these cases also developed cramp, the essential AVERAGE DURATION OF SYMPTOMS OF PROLAPSED DISC cause seems to be degenerative changes in the nerve root due to section or a http://jnnp.bmj.com/ n Average duration stretching by prolapsed Series No.series of symptoms disc. -before oper'atio'n Discussion Pre-operative cramps .. 16 3 yrs. 5 mths. From the results of this study, it seems that cramp is more likely to occur in cases of prolapsed Postoperative cramps: intervertebral disc when there is involvement of the with root section .. 43 4 yrs. 10 mths. posterior nerve roots by prolapsed material as in

without root section . 9 5 yrs. 9 mths. large lateral protrusions. That cramp can occur on October 1, 2021 by guest. as a result of posterior root irritation is well known Total .. .. 52 4 yrs. 11 mths. and is an explanation of their frequency in such a condition as subarachnoid himorrhage. Gootnick Cases without cramp pre- (1943) believes that the cramps seen in arthritis of or postoperative .. 136 3 yrs. 9 mths. the hip or knee, in weak feet, or in intrinsic in- flammatory changes in nerves, such as sciatica, Whole series .. .. 204 4 yrs. 1 mth. are clonic contractions of a muscle group due to G J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from 256' LIONEL- WOLMAN reflex bombardment of the myoneural junction by muscle will go into cramp after divisioni of its a stream of impulses from the neighbouring source sensory root. The observations recorded in this of irritation, and he likens them to a variety of paper suggest that there may be some correlation segmental visceromotor reflex, such as the abdominal between nerve root divided and muscle affected, rigidity in peritoneal inflammation. This theory but there were exceptions, as was expected from the would explain the occurrence of cramp in the overlap between the segments and muscles inner- pre-operative patients. In the postoperative patients vated. Weddell'(1945) has shown in the case of the cramp seems to be related to posterior root pain sensation in normal skin that there is a network division. Although posterior rhizotomy is an of nerve endings arranged so that any one area of operation which has been practised for a long time skin is supplied by several overlapping terminals for various painful conditions, no mention of the derived from different areas. In muscles the nerve incidence of cramp after operation could be found terninals form a much looser meshwork, so that on perusal of the literature. After division of the individual neural terminals in this meshwork are posterior nerve root three possible series of changes isolated from each other (Feindel, Weddell, and may occur: a peripheral, a central, and changes Sinclair, 1948). The utilization of intact reflex at the site of section. These will be considered in arcs in cramp production might be possible with turn. this anatomical arrangement, while the reduction Dividing the posterior root should, theoretically, in pattern of afferent impulses after rhizotomy leave the dorsal root ganglion, its afferent sensory might form a basis for explanation of the pain fibres, and their terminal sensory endings in muscle associated with these cramps, as has been postulated intact, all degeneration occurring proximal to the in the case of nerve nets and terminals subserving. cut. If there are efferent autonomic fibres in the cutaneous pain sensation when isolated from' posterior root, after section it is possible that some neighbours, instead of interweaving with them as' peripheral degenerative changes may occur, affecting in normal skin (Weddell, Sinclair, and Feindel, either the muscle fibres, the sensory endings, the 1948). The possibility that the painful elementProtected by copyright. in myoneural junction, or the blood supply, and cramp is transmitted to the cord through intact rendering the muscle fibres more liable to pass into posterior roots via sympathetic afferent sensory spontaneous contraction. This might be trans- fibres in these rhizotbmy cases cannot be excluded. mitted to other fibres in the muscle until spasm The central changes would consist of degeneration resulted under various sets of conditions. The of the sensory fibres as they entered the cord as far existence in man of sympathetic fibres in dorsal as the intercalatory neurone in the posterior horn roots has not been proved, while the presence of or even to the anterior horn cell. Loss of con- parasympathetic fibres arising in the lateral horns trolling action of afferent impulses would have an of grey matter, and running to single end plates in effect on these neurones and might cause them to muscle via dorsal root and ganglion (Kure, 1931), send out impulses to the muscles, resulting in tkeir is not universally accepted. Apart from these spasm. The pain of thle cramp would havee'to possibilities it is difficult to conceive how peripheral utilize intact sensory fibres at other levels as, chang'es may occur by other known mechanisms, described above. The poiterior root degeneration though their occurrence cannot be excluded. could be compared with the pathological changes Dawson and Ladell, in a personal communication, occurring in tabes dorsalis. -In this disease, over stated that they found the cramp produced by 90 per cent. of all cases exl*rience lightning pains acute salt deficiency was relieved by an intravenous and " an abrupt reflex or half-6onscious 'start' ofhttp://jnnp.bmj.com/ injection of salt, except in a leg from which the limb muscles may accompany the 'shoot' of 'the circulation had been cut off by a pneumatic cuff. pain " (Wilson, 1940). The p6riodic occurrence of When circulatory arrest had abolished both the painful crises associated with spasm ofsmooth muscle anlkle jerk and the reflex responses to electrical also, demonstrates the motor accompanimnent'-of stimulation, cramp no longer occurred, either during changes in the posterior nerve roots. It seems more electrical stimulation or duiring voluntary contrac- likely, therefore, that the' motor component of'these tion of the muscle. This suggests that an intact cramps is dependent on central degenerative changes reflex arc is necessary for the objective and subjective rather than hypothetical peripheral alterations. on October 1, 2021 by guest. phenomena of cramp to be present together. 'If The third factor to be considered is the change in this is true, the cramp in rhizotomy patients is the cut surface of the nerve root or in the cases with dependent on intact reflex arcs in other segnents of pre-bperative cramp the site of impingement of the cord. Unfortunately, there is no muscle which prolapsed disc on nerve root. Granit and others is innervated entirely by one.segmental level of the (1944) showed that an "artificial synapse" could cord, so it is not possible to prove whether such a be formed in a mixed nerve either'by sectioning it J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.12.3.251 on 1 August 1949. Downloaded from

CRAMP AND PROLAPSED DISC 257 or even ligating it without damaging it enough to studied in a series of 204 cases followed up one to stop normal distal conduction. This may be the *seven years after operation. mechanism of pain and cramp production in these 2. The incidence of cramp was found to be cases, the affected nerve or the peripheral end of the higher after operation when, in addition to removal sectioned posterior root acting as a short-circuiting of the protruded disc material, a posterior nerve point causing impulses to descend perhaps anti- root has been cut. dromally. One point needing further explanation is why the 3. The cramp occurring in these postoperative cramps diminish with time. If they are due to cases gradually diminished with time. changes in the muscle fibres or in sensory endings, 4. The significance of these findings is discussed are these changes reversible with -the passage of in relation to the mechanism of cramp production. time, or do other intact fibres take over their 5. The occurrence of cramp, whether before or functional connexions ? If the cramps are -due to after operation, is of no prognostic significance as changes in the cord, is their gradual diminution readthopaivrsu.regards the operative result duedyeto oco'mpletioncopletonofo degenerativedegneraive changeshangs ininthethe 6. not helping in elucidating the mechanism cut fibre and its connexions, or is it due to the time of crampWhile, thesfdg ifconfime mustnbe neededneeddforfrotheroherfibesfibres andnd nervenrveendngsinendings in ~hetakenthe ofcapthsfidn,ifofrminto account in any comprehensive,mutbtheory of cord to take over completely the functional con- camp. nexions with released neurones? Such questions cannot be answered at present, and further specula- My thanks are due to Mr. James Hardman, F.R.C.S., tidon would be unprofitable. Thus, the observations without whose work and original suggestion, this made in this paper, though interesting, do not help investigation would not have been undertaken. holding in thp elucidation of the problem of cramp. Never- theThisE. workG. Fearnsideswas carriedResearchout by theScholarship,author whileUniversity theless, if they are confirmed, they would have to of Cambridge. Protected by copyright. be taken into account in any theory ofthe mechanism REFERENCES of cramp. Bradford, F. K., and Spurling, R. G. (1941). "The Quinine, which was suggested by Gootnick (1943) Intervertebral Disc." First Edition. Charles C. as being effective in cramp due to reflex irritation, Thomas, Springfield, Illinois. p. 74. was not tried in the present series. By the time Feindel, W. H., Weddell, G., and Sinclair, D. C. (1948). J. Neurol. Neurosurg. Psychiat., 11, 113. these patients were seen the cramps had become Gootnick, A. (1943). Arch. int. Med., 71, 555. infrequent, .so that no therapy was necessary; Granit, R., Leksell, L., and Skoglund, C. R. (1944). even if quinine had been given, its efficacy would Brain, 67, 125. have been difficult to assess owing to the natural Kur6, K. (1931). "Die vierfache Muskelinnervation improvement that was taking place. einschliesslichMuskeldystrophie."der Pathogenese undUrbanTherapieand Schwar-der InInoneonepatientpatientseenseenafteraftethisthisfollprogressivenfOllOW-Up, in whom zenberg. Berlin. severe cramp was a prominent symptom and in Lenhard, R. E. (1947). J. Bone Jt. Surg., 29, 425. whom it persisted after the response of the sciatica O'Connell, J. E. A. (1943). Brit. J. Surg., 30, 315. to conservative treatment, quinine was very effective. Pemberton, R. (1935). " Arthritis and Rheumatoid This patient later needed surgical treatment owing Cox, London. p. 51. to the recurrence of sciatica. Walker, E. (1945). South. med. J., 38, 832.

Weddell, G. (1945). British med. Bull., 3, 167. http://jnnp.bmj.com/ Summary and Conclusions -, Sinclair, D. C., and Feindel, W. H. (1948). J. Neurophysiol., 11, 99. 1. -The occurrence of cramp as a symptom in Wilson, S. A. K. (1940). "'Neurology." Edward Arnold, sciatica due to prolapsedd iervertebral disc was London. p. 491.

BOOK IRIEVIEWS ObservationSeon the Pathology of Hydrocephalus. By and (3) failure of adequate absorption of fluid into the on October 1, 2021 by guest. Dorothy S. Russell. 1949. M.R.C. Special Report. blood and lymph channels. Recent work discounts the Series No. 265. London, H.M. Stationery Office. first possibility, as it seems unlikely that either hyper- Pp. 138. Price 6s. net. trophy of the choroid plexuses or increased capillary This monograph is the result of seventeen years of pressure in them, for example, as a result of thrombosis post-mortem study of hydrocephalus in the child and the of their efferent veins, ever result in hydrocephalus. adult. There are three possible causes for hydro- About the third possible cause there is no certain cephalus: (1) excessive formation of the cerebrospinal knowledge, but a number of clinical cases of dilatation fluid; (2) interference with the circulation of the fluid; of the ventricles, as a sequel to extensive sinus throm-